The main function of insulators is to achieve electrical insulation and mechanical fixation, for which various electrical and mechanical performance requirements are specified. For instance, under the action of the specified operating voltage, lightning overvoltage, and internal overvoltage, no breakdown or surface flashover occurs; under the specified long-term and short-term mechanical loads, no destruction or damage is caused; after long-term operation under specified mechanical, electrical loads, and various environmental conditions, no significant deterioration occurs; the hardware of the insulator does not produce significant corona discharge under the operating voltage to avoid interference with radio or television reception. Since insulators are widely used, their connecting hardware is also required to be interchangeable. Additionally, the technical standards for insulators necessitate various electrical, mechanical, physical, and environmental condition tests based on different models and usage conditions to verify their performance and quality.